DESCRIPTION (provided by investigator): In 1997, there were an estimated two million breast cancer survivors alive in the United States. Historically, many clinicians have believed that surveillance radiographic and laboratory testing for recurrent disease should be carried out routinely. However, more recent randomized trials and professional society guidelines have made it clear that while mammograms should be done annually, other tests should only be done to evaluate symptoms or signs. Evidence exists of problems with the quality of surveillance care for breast cancer survivors: under use of mammography, and over use of non-routine laboratory and radiographic tests. This project will use population-based Surveillance, Epidemiology, and End Results (SEER) Tumor Registry data linked to Medicare claims to evaluate determinants of the quality of care of older breast cancer survivors. The specific aims of this study are: 1. Describe patterns of surveillance testing (mammograms, chest radiographs, bone scans, CT scans, liver function tests) among older breast cancer survivors, and among age-matched control subjects. 2. Assess the effects on surveillance testing rates of the publication of two randomized trials in 1994 showing the lack of effectiveness of intensive surveillance testing. 3. Assess the effects on surveillance testing rates of health care delivery factors, such as the presence of a majority of care provider (a physician providing the majority of the patient's office visits), and co-managed care (management by both a primary care provider and an oncology specialist). 4. Assess the effect on surveillance testing rates of provider characteristics (e.g. age, gender, specialty) and of patient characteristics (e.g. race, socioeconomic status, initial therapy). The results will yield important public policy information regarding breast cancer surveillance care.